The present invention relates generally to the use of settable slurries in the construction industry for providing level underlayments for floors, walls etc., and more specifically provides a system for reliably determining the degree of dryness of such slurries prior to the application of a final surfacing material such as, but not limited to tile, sheet vinyl, wood, carpet, wall covering or the like.
In the construction industry, whether in new construction or remodeled spaces, before a final surface coating or covering is applied, including but not limited to tile, sheet flooring, wood flooring, carpeting, a leveling product is typically applied to level the base floor in preparation for the final coating. One such product is sold under the brand LEVELROCK® by United States Gypsum Company, the owner of the present invention. LEVELROCK® compound is a gypsum based product which is mixed with water and sand to form a pourable slurry that is applied to floors for leveling purposes. It is important to users of LEVELROCK® compound or similar products that the product is sufficiently dry prior to applying the final surfacing material. If the product is not dry enough, the moisture has been known to attack the bonding agent of certain adhesives, causing the final surfacing material to fail to properly adhere to the leveling product or the substrate. In some cases, buckling or blistering of the final surfacing material may result. Since the drying process of such leveling compounds may take several days, it is important for construction budgeting and workload considerations that the appropriate moisture level be accurately determined as soon as possible.
One attempted solution of this problem is to employ moisture meters to determine the relative dryness of the leveling product. Such meters are typically used in construction, home inspections or similar activities for measuring the moisture level of wood or concrete. Such meters have proved unsatisfactory in reliably measuring the relative dryness of leveling products, since the values displayed often do not accurately reflect the dryness of leveling compounds in general, and also for the specific product, because the meters are not commonly designed for such readings. In addition, meters vary in sensitivity among manufacturers, and also between units of the same manufacturer and model.
In the wallboard manufacturing process, relatively sensitive moisture meters have been employed for determining the desired moisture characteristics of setting wallboard on a wallboard manufacturing conveyor line. Prior to installing the meters upon a conveyor line, it is known to use spacers representing the desired wallboard thickness in calibrating the meter. Exemplary spacer thicknesses are 0.25 inch, 0.5 inch, 0.75 inch, representing standard wallboard thicknesses. The spacers are manufactured of phenolic plastic, which has a dielectric, or inherent radiation deflecting properties which simulate moderately wet wallboard. Calibration is performed by generating two values, a first based on the dielectric of air, creating a “zero” value, and another value using the spacers, approximating the moderately wet wallboard. In such applications, once calibrated, the meter monitors moisture content from a specified distance from the wallboard surface. In some applications, the spacers have been replaced by merely moving the meter farther from the surface of the wallboard.
Such an arrangement has proved unsuitable for use in monitoring the moisture content or relative dryness of setting leveling compounds. One disadvantage of the above-described system is the fixed mounts for the meters to obtain a specified distance from the substrate, which is unsuitable for floor applications. Also, the nature of the meters used for wallboard monitoring is overly costly and cumbersome for use by flooring contractors. Furthermore, while wallboard moisture characteristics are fairly consistent, flooring contractors typically employ a variety of products depending on the application. There is a great variety in the drying characteristics among these various products, which defies consistent monitoring by the existing systems.
Thus, there is a need for an improved system for more accurately determining the relative dryness of leveling product prior to application of a final surfacing material. There is also a need for such an improved system which is usable with moisture meters from a variety of manufacturers. In addition, there is a need for an improved system of moisture monitoring which accommodates the variation in commercial products.